Relationship between the number of tapping-induced secondary laticifer lines and rubber yield among Hevea germplasm

The lack of suitable early selection parameters means that traditional rubber breeding for yield is time consuming and inefficient. Laticifer is a tissue specific fo natural rubber biosynthesis and storage in rubber tree. The number of the secondary laticifers in the trunk bark tissues is positively correlated with rubber yield in the matured rubber trees that are regularly tapped. In the present study the rubber yield from 280 of 4–5 year-old virgin trees from7 cross combinations was compared with the number o newly differentiated secondary laticifers caused by tapping. Results showed that the number of tapping induced lines of secondary laticifers varied in differen germplasm and was positively related to the rubber yield indicating this could be used as a suitable parameter fo early evaluation of yield potential of rubber trees.

Economic Benefits of Rubber Plantations in Longjiang Farm in Hainan by the Application of Optimized Fertilization Formula

The influence of formula fertilization optimization on dry rubber yield and economic benefits of the rubber plantation in Hainan Longjiang Farm were studied by using ＂contrast＂ design method of fertilizer field experiments. The results showed that the actual production rate reached 4.61% and the net production rate of dry rubber reached 3.97% by application of optimized fertilization formula. Analysis of variance showed that the average dry rubber yield in optimization of formula fertil- ization area was significantly higher than that of conventional area. The results also indicated that the optimization of formula fertilization had obvious economic benefits, and each rubber tree reduced cost and increased 9.95 yuan on average after the test.

Effects of Secondary Chamber on Gas Yield by Pre-Vacuum Chamber Pyrolysis of Rubber Wood

Global warming awareness criticizes further usage of fossil fuels and insists promotion of renewable energy usage. Additionally, many people in rural areas of developing countries cannot access electricity. To solve this sort of energy crisis including global warming, current authors developed a proto-type of a pyrolysis plant equipped with a prevacuum chamber, which can be used to produce combustible gases for an engine generator in rural areas where people cannot access electricity. The plant is simple and easily maintained in consideration of special conditions that a rural area can receive very few maintenance service, technical assistance, and supply of spare parts. However, gas yield obtained by the proto-type of plant was around 20 wt% of feedstock. One way to enhance gas yield from this proto-type of plant is to utilize reaction of secondary tar cracking. This research work aims to examine possibility of gas yield enhancement keeping a simple structure of the proto-type of plant and using a simple technique of secondary tar cracking. Two tar cracking methods are examined: one is homogeneous tar cracking and the other is heterogeneous tar cracking using catalysis. In the homogeneous tar cracking, pyrolysis gases must be heated up to 650oC to 700oC and in the heterogeneous tar cracking, wood char is used as catalysis, because wood char is byproduct of pyrolysis. It is concluded that the homogeneous tar cracking is quite unlikely in the secondary chamber, but on the other hand, heterogeneous tar cracking using wood char can produce 30 wt% of gas yield from 1 kg of feedstock.

地膜覆盖对胶园间种珠芽黄魔芋光合生理特性及产量的影响

为了解不同地膜覆盖对胶园间种的珠芽黄魔芋(Amorphophallus muelleri)叶片光合生理特性、土壤物理性状及产量的影响,本研究设置银色地膜、黑色地膜、白色地膜、防草席、加厚黑色地膜、微孔黑色地膜和无覆盖(CK)共7个处理,测定分析魔芋换头期、膨大期和成熟期3个时期叶片的光合特性参数:净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(T_(r))、胞间CO_(2)浓度(Ci)、电子传递速率(ETR),生理特性参数:可溶性蛋白(SP)含量、可溶性糖(SS)含量、叶绿素(Chl)含量、叶绿素a/b(Chl a/b),土壤原位物理性状参数:土壤含水量(SMC)、土壤电导率(SC)、土壤温度(ST),并测定魔芋地下球茎产量的变化。结果表明:同一时期不同地膜覆盖处理均提高了魔芋叶片的光合参数(P_(n)、G_(s)、T_(r)和ETR),换头期和膨大期防草席处理的P_(n)、Gs和T_(r)均显著高于其他处理(P<0.05),而其他处理间不规律上下变幅,其间有显著差异;除了成熟期,同一时期不同地膜覆盖处理魔芋叶片的SP和Chl均显著高于对照,各处理间无显著差异;同一时期不同处理魔芋叶片的SS和Chl a/b变化趋势稍有不同,成熟期各处理的SS均显著高于对照,3个时期对照的SS均最低,而成熟期地膜处理的Chl a/b较对照均无显著差异;同一时期不同地膜覆盖的SMC和SC均高于对照,加厚黑色地膜处理保水效果最好,膨大期微孔黑色地膜处理和成熟期防草席处理的SC均显著最高,其他处理间的SMC和SC无显著差异。同一地膜覆盖处理不同时期的P_(n)、G_(s)、T_(r)、ETR、SP、和Chl均表现为换头期>膨大期>成熟期,而各处理的SS和Chl a/b表现为成熟期>膨大期>换头期。经所有指标和产量相关性分析的结果来看,除了ST与产量呈负相关外,其他指标与产量均呈正相关。不同地膜覆盖较对照均提高了珠芽黄魔芋产量,银色地膜、黑色地膜、防草席和加厚黑色地膜处理增产效果明显,而白色地膜和微孔黑色地膜处理增产不明显。因此,在实际生产中,采用银色地膜、黑色地膜、防草席和加厚黑色地膜都是魔芋增产增效的可行选择。

控释尿素与普通尿素配施对橡胶树叶片和胶乳养分及产量的影响

为了明确控释尿素与普通尿素配施在橡胶树上的应用效果,通过2年田间试验,研究了减氮条件下控释尿素与普通尿素不同比例配施对橡胶树产量、叶片和胶乳矿质养分及土壤氮含量的影响,为橡胶树栽培管理中合理施氮提供技术支撑。结果表明:控释尿素与普通尿素配施可提高橡胶树干胶产量和叶片氮含量,与常规施肥相比,橡胶树干胶产量增幅为16.28%~39.13%(2021年)和7.94%~9.69%(2022年),叶片氮含量增幅为10.54%~19.17%(2021年)和10.24%~21.50%(2022年),控释尿素与普通尿素配施处理叶片氮含量均处于正常值以上。控释尿素与普通尿素配施还能够增加胶园肥穴土壤碱解氮含量,较常规施肥增加了11.27%~80.36%。控释尿素与普通尿素配施比例为50∶50时,橡胶树干胶产量(2022年)、叶片氮含量(2021—2022年)和土壤碱解氮含量(2021—2022年)均显著高于常规施肥。综上所述,在本试验条件下,控释尿素与普通尿素配施比例为50∶50能够获得较高的干胶产量,可改善叶片营养状况,维持土壤氮水平,有利于实现橡胶树施肥管理的绿色协同增效。

海南岛天然橡胶产量和气候适宜度相关性研究

使用气候适宜度指数方法对海南岛橡胶树气候适宜性进行评价,并选择去趋势互相关分析(DCCA)方法对橡胶树单产和气候适宜度进行相关性分析。结果表明:海南岛橡胶单产在东部和西部较低,最低值出现在文昌,为657.30kg·hm^(-2);最高值为三亚的1376.54kg·hm^(-2)。海南岛中部单产的变化幅度较小,其余地区单产均呈明显增加趋势,线性倾向率普遍超过10 kg·hm^(-2)·a^(-1)。海南岛中部和东部综合适宜度水平较高,适宜度指数超过0.70,西部适宜度水平较低,为0.39;温度和光照适宜度指数空间差异小,整体在0.80和0.70以上;降水适宜度指数在中部和东部较高,西部南部偏低,数值在0.42—0.77之间;风速适宜度在中部和南部超过0.75,在西部和北部适宜度指数偏低,最低达到0.18。DCCA分析结果显示,气候适宜度与橡胶单产存在明显的长程相关关系,降水和产量的相关性最高,风速相关性最低;空间上,东部相关性较低,西部、北部和和南部相关性稍高。

4个引进橡胶树胶木兼优品种比较试验

为了能够客观地筛选出适合我国植胶环境的橡胶树胶木兼优新品种,基于品种比较试验对4个国外引进品种‘热试09-5’‘热试09-6’‘热试09-7’和‘热试09-10’的产量及副性状进行综合评价。结果表明,4个参试品种中,‘热试09-7’表现出速生性状,4个参试品种的产量特性不明显,仅‘热试09-5’在开割第1年与对照相当,其他年份均低于对照。胶乳生理参数分析结果表明,‘热试09-5’的干胶产量、排胶初速度与对照差异不显著,而蔗糖含量低,硫醇含量高,认为该品种产胶潜力大,胶乳稳定性好,排胶快,糖利用率高。‘热试09-6’原生皮厚度较厚,树皮中乳管列数多,与‘RRIM600’相比,干胶含量、堵塞指数高,排胶初速度和蔗糖含量差异不显著,认为该品种有较好的产胶潜力,但胶乳代谢强度低,可考虑通过刺激提高代谢强度,达到增产的目的;各参试品种的生胶性能、硫化胶的物理机械性能及分子量和分子量分布差异分析结果表明,不同指标参数在品种间存在差异,‘热试09-5’的塑性初值最低,塑性保持率最大,‘热试09-6’门尼粘度最高,‘热试09-5’最低,‘热试09-7’有较大的重均分子量,呈现出较好的物理机械性能。在抗逆性表现方面,‘热试09-5’的风害断倒率最小,‘热试09-10’最高;抗寒前哨数据结果表明,在对照品种‘93-114’无寒害发生的情况下,‘热试09-5’寒害等级为1.00,‘热试09-7’为0.17。综合分析表明,4个引进品种的速生性状明显,‘热试09-6’有较好的产胶潜力,‘热试09-5’的抗风性优于对照,‘热试09-7’的寒害适应能力较好。综上表明‘热试09-6’综合性状较好,适合在海南中西部轻风区生产性试种。

Research on Development of Natural Rubber in Indonesia

Through analyzing the harvested area,yield and total production of natural rubber and the exports of dry rubber,the situation of rubber cultivation in Indonesia was studied,and the development prospects of natural rubber in Indonesia were explored. The results showed that the harvested area of natural rubber in Indonesia showed a wave-like rise from 1980 to 2016. The area harvested in 2000 was increased by47. 06% compared with that in 1980,and the area harvested in 2016 was increased by 6. 43% compared with that in 2008. The yield of natural rubber in Indonesia showed a dynamic trend from 1980 to 2016. It reached the maximum( 993 kg/ha) in 2007 and reached the minimum( 575 kg/ha) in 1982. The total production of natural rubber in Indonesia showed a wave-like rise during 1980-2016. The total production of natural rubber in 2000 was increased by 47. 06% compared with that in 1980,and the total production of natural rubber in 2016 was increased by 110. 67% compared with that in 2000. The export volume of dry natural rubber in Indonesia basically showed a concussive rise from 1980 to 2016. The proportion of export volume in the total production in 2016 declined by 14. 75% compared with that in 1980. It is believed that the harvested area of natural rubber in Indonesia will be near the peak in the next few years,and it is difficult to increase the output; the proportion of exported natural rubber in the total production will decline slowly; and the potential for natural rubber development is large.

化肥减施下橡胶树有机肥替代用量研究

为实现橡胶树种植化肥减量增效的目的,在云南东风农场橡胶林开展不同有机肥替代化肥用量试验研究。结果表明:与单施配方肥相比,有机肥替代提高了土壤pH值及团聚体、有机质、全氮、有效氮含量。其中,60%配方肥+15 kg有机肥处理的pH、有机质、水解氮、团聚体指标显著高于单施配方肥处理,但有效磷、速效钾含量与单施配方肥处理差异不显著;叶片N、P、K、Mg养分含量与单施配方肥处理相当;年增产干胶5%,减少配方肥投入144 kg·hm^(-2)。通过综合评价,推荐60%配方肥+15 kg有机肥为橡胶树有机肥替代化肥的最佳用量。

Analysis of Rubber Planting in Malaysia

There are state-owned and privately-owned rubber plantations in Malaysia,of which most of them are privately owned. In Malaysia,most rubber gardens are small,and the ratio of small rubber gardens to large rubber plantations is approximately 10∶ 1. In Malaysia,the plating area of rubber trees was only 4 200 ha in 1900,1. 30 million ha in 1961,and 1. 07 million ha in 2014. It was the highest in 1978,up to 1. 89 million ha. It was the lowest in 2010,only 1. 02 million ha. The per unit area yield of rubber in Malaysia was 6 074 hg/ha in 1961 and 6 274 hg/ha in 2014. The maximum 10 285 hg/ha appeared in 1987,while the minimum 5 492 hg/ha appeared in 1999. The per unit area yield of rubber in Malaysia fluctuated greatly. Rubber yield in Malaysia was 790 000 t in 1961,and it was the highest in 1988( 1. 66 million t) and the lowest in 2014( 670 000 t).

Study on Natural Rubber Development in Thailand

This paper firstly introduced the development prospects of natural rubber in Thailand,discussed the general situation of rubber tree planting in Thailand,and analyzed the natural rubber harvested area,per unit area yield,yield and natural rubber exports in Thailand. The results showed that the annual average natural rubber harvested area in Thailand increased by 1. 21% from 1980 to 1990; the annual natural rubber harvested area increased by 4. 27% from 1991 to 2011; the annual average natural rubber harvested area in 2012-2016 increased by 5. 65% per year; from 1980 to 2004,the per unit area yield of natural rubber in Thailand showed a rising trend,and rubber yield from 2005 to 2016 showed a decline trend; from 1980 to 2016,Thailand's natural rubber yield showed a wave-like rise. In recent years,natural rubber production has changed little. In 2015,the yield fell by 2. 19% compared with 2014,and in 2016 it increased by 0. 22% compared with 2015;from 1981 to 2016,the export volume of natural rubber in Thailand basically showed a trend of rising with large fluctuation. In recent years,the export volume of natural rubber in Thailand accounted for 74%-82% of natural rubber yield in that year. Finally,it is found that the harvested area of natural rubber in Thailand will continue to decline in the next few years,it is difficult to increase the yield,the proportion of natural rubber exports and yield will gradually decline.

保水剂施用量对胶园土壤微生物和土壤酶活性及产量的影响

【目的】探明保水剂对胶园土壤生物活性及橡胶树产量的影响,探索适合开割橡胶树抗旱和高产的保水剂用量,为橡胶树抗旱高产栽培技术研究提供支持。【方法】以15割龄的橡胶树热研7-33-97为材料,采用田间试验,以不施用保水剂为对照(CK),比较不同保水剂施用量(T1:60 g/tree、T2:120 g/tree、T3:180 g/tree、T4:300 g/tree)对胶园土壤pH、水分、养分、微生物数量、酶活性以及橡胶树胶乳产量的影响。【结果】施用保水剂提高了胶园土壤含水量和速效养分含量,但对土壤pH无影响;同时还促进土壤细菌数量、放线菌数量和微生物总量增加,但未改变土壤中细菌、放线菌、真菌的总体比例,土壤微生物仍以细菌为主;不同处理土壤酶活性和橡胶树胶乳产量随着保水剂用量增加呈单峰曲线态势。细菌数量、放线菌数量、脲酶活性、转化酶活性、过氧化氢酶活性、氨态氮含量、速效磷含量、橡胶树干胶产量均随着保水用量增加呈先增后降趋势,且各处理中以T2用量对提高胶园土壤微生物数量和酶活性、增加橡胶树产量效果最佳;与CK相比,T2处理的土壤细菌与放线菌数量分别增加346.42%、191.48%,而土壤真菌数量减少15.31%,土壤脲酶、转化酶和过氧化氢酶活性分别提高40.01%、15.74%、31.44%,橡胶树干胶产量增加11.99%。【结论】在开割胶园施用保水剂,推荐施用120 g/tree,有利于提高土壤含水量,增加土壤微生物数量和养分含量,促进橡胶树胶增产。

金属橡胶桥梁支座剪切屈服后刚度研究

基于重叠面积法与Haringx理论,得到圆形截面金属橡胶桥梁支座剪切屈服后刚度的计算公式,公式中剪切屈服后刚度与压应力及支座直径成正比,与支座高度成反比,并且存在待求系数α与β。通过大尺寸金属橡胶桥梁支座试件的压缩及压剪试验,获得剪切模量与压缩模量之间的关系,求得系数α约为1.3。参考剪切试验中压应力、支座直径、相对密度和形状系数对支座剪切屈服后刚度的影响规律,给出无量纲系数β的计算公式。根据待求系数α与β,对理论计算公式进行实用性简化,并比较屈服后刚度的理论计算结果与试验结果。结果表明:实用计算公式与试验结果吻合较好,且具有较好的精度,可用于金属橡胶支座压剪状态下屈服后刚度的计算。

种芋大小对德宏成龄胶园林下珠芽魔芋生理特性及产量的影响

为选出德宏地区成龄胶园林下种植珠芽魔芋的最适大小种芋,对不同大小梯度的种芋在生长过程中的形态指标、生理指标及产量进行测定及分析。结果表明:珠芽魔芋地上部分长势与种芋大小存在正相关性,种芋大小在200~250 g的株高、叶盘直径、叶柄直径、顶裂叶长、顶裂叶宽的测定值均为最大;产量随种芋大小增大而提高,种芋大小>100 g对产量的影响有明显差异,种芋大小为50~100 g的单株产量与叶盘直径呈显著正相关;珠芽魔芋叶片合成和叶绿素积累与种芋大小无明显关系;种芋大小在200~250 g的可溶性蛋白含量显著低于其他处理,生理活性最低。在德宏州成林橡胶林下种植珠芽魔芋推荐使用150~200 g大小的种芋,在节约成本的同时可显著提高产量和生长势。

橡胶树日间割胶试验初报

为探究日间割胶对不同品种橡胶树产量、胶乳品质和生胶性能的影响,以广东茂名垦区团结农场6个橡胶树生产性栽培品种为试验材料,设定3个日间割胶时间处理,以传统的凌晨4:00割胶为对照,分析株次干胶产量、胶乳生理参数和生胶性能指标随割胶时间的变化趋势。结果表明:经双因素方差分析,产胶量受割胶时间和橡胶品种交互作用影响差异达显著水平,各生理参数对品种响应存在显著差异,对割胶时间响应不存在显著差异。干胶产量随日间割胶时间推移呈下降趋势,生理参数及生胶性能指标在各品种间变化趋势不尽相同。本研究设置的3个时间处理,最适合日间割胶的时间为早晨6:00;6个参试品种中,以胶乳体积、干胶产量和生理参数为评价指标,最适宜日间割胶的品种为热垦524和热垦525;以生胶常规指标及生胶性能为评价指标,最适宜日间割胶的品种为热研7-33-97和热垦501。综合考虑以提高劳动效率,增加胶工收入为目的,因此,本研究认为广东茂名垦区产胶高峰期可选用热垦524和热垦525于早晨6:00进行日间割胶生产。

加载频率与幅值对橡胶隔震支座力学性能的影响试验研究

为了探究加载频率、幅值对橡胶隔震支座水平等效刚度、特征强度、屈服后刚度、等效阻尼比及耗能等力学性能的影响,在实验室常温(25℃左右)环境中对直径为700 mm的典型常用天然橡胶支座和铅芯橡胶支座(共4个)进行了一系列的压剪试验,其中,加载频率变化范围为0.3~0.67 Hz,加载幅值变化范围为25%~250%。考虑到试验中加载设备摩擦力与惯性力的影响,本文对实测水平力进行修正并绘制出隔震支座的真实滞回曲线。实验结果表明:支座内部温度随加载频率的增大,升温越为明显,其中在最大加载频率下,天然与铅芯支座在前三圈循环下的升温幅度分别为5.24%和29.98%;随着加载幅值从25%~250%不断增大,隔震支座水平等效刚度和屈服后刚度的最大下降幅度分别为67%和55%,特征强度的增长幅度范围为64%~188%,且天然与铅芯支座耗能约增加15~26倍;此外,铅芯支座的内部温度上升幅度和各项力学性能均明显高于天然支座,但随着加载进行,铅芯支座的特征强度出现了更为明显的刚度退化,且在前三圈循环加载中天然与铅芯支座的特征强度分别退化了3.34%和12.2%。

橡胶树品种‘云研77-4’在广东茂名适应性调查

广东植胶区地处热带北缘,橡胶生产过程中低温寒害是主要自然灾害之一,严重的寒害对橡胶产业会造成毁灭性打击,因此引种抗寒品种具有重要意义。通过多年多点调查橡胶树品种‘云研77-4’在广东茂名地区的表现,结果表明:与抗寒品种‘IAN873’相比,‘云研77-4’开割前后的年均生长量都高于‘IAN873’,证明‘云研77-4’整体的长势优于‘IAN873’;在寒害发生后,其受害级别低于‘IAN873’;在台风发生后,‘云研77-4’的受害级轻于‘IAN873’,但抗风性一般,对于风害发生严重的地区,不适宜引种;开割后随着年限增加,产量稳步提升,产量表现优于‘IAN873’。因此,在广东茂名植胶区,‘云研77-4’在寒害发生较重的区域适宜栽植,台风灾害重的地区不建议栽植。

丁基橡胶胶乳制备工艺的优化

以丁基橡胶(IIR)为原料,采用“溶解-乳化”法制备了稳定性较好的IIR胶乳,考察了乳化剂种类、乳化剂组成、pH值、油水质量比、浓缩工艺等对乳化效果和IIR胶乳产率的影响。结果表明,优化的IIR胶乳制备的乳化剂配方及制备工艺如下:乳化剂为油酸钾和Triton X-100,二者质量比为4/1;当体系pH值为10,油水质量比为4/5时,得到的IIR乳液稳定性最佳,胶乳产率最高;采用膏化工艺进行胶乳浓缩,以藻酸钠为膏化剂,占胶乳中橡胶质量分数为0.6%时浓缩效果最好;并采用离心分离工艺缩短浓缩时间,当转速为1500 r/min,离心时间为20 min时,可获得总固物质量分数约为55%的IIR胶乳,胶乳产率达90%以上。

橡胶树胶木兼优无性系生长量与产量的测定与分析

对中国热带农业科学院橡胶研究所引进的胶木兼优品系和自育的新型无性系及高产对照品种RRIM600组成的15个试材从生长量和产胶量性状进行比较分析和初步评价.结果表明:15个无性系在不同月份的干胶含量和割次干胶产量分别存在极显著或显著差异,不同无性系的割次干胶产量和月产干胶量均存在较大差异,大部分材料间生长量、胶乳产量和干胶含量差异未达显著性水平,生长量与产胶量无显著性相关.而且,热试8、热试7、热试10和热研2-73这4个无性系表现出良好的胶木兼优特性.

死皮康复营养剂恢复橡胶树热研7-33-97死皮植株产胶能力的效果分析

以橡胶树无性系热研7-33-97为试验材料,分析了死皮植株在施用死皮康复营养剂,复割后的产胶情况,以评价死皮康复营养剂的施用效果。结果表明,死皮恢复植株在复割后的3 a中,干胶含量变化不大;2014~2016年,死皮指数总体呈上升趋势,分别为15.33、24.55和33.07,而年平均单株干胶产量则呈下降趋势,分别为55.67、44.22和35.53 g/(株·刀),二者变化趋势相反。从恢复植株和正常树月平均单株干胶产量的比较结果来看,除2015年7月外,其余各月恢复植株平均单株干胶产量均高于正常树,而年平均单株干胶产量二者均呈逐年下降趋势,但恢复植株干胶产量均高于同年份的正常树,2014年、2015年和2016年正常树平均单株干胶产量分别为37.71、32.27和26.75 g/(株·刀),分别低于恢复植株约18、12和9 g/(株·刀);恢复植株各月和各年份平均单株干胶含量均高于正常树。这些结果说明,死皮康复营养剂对橡胶树死皮具有较好防治效果,且具有一定的生产持续性。